OCCURRENCE OF TARNISHED PLANT BUG POPULATIONS WITH TWO INTENSITIES OF DIAPAUSE INTHE MISSISSIPPI RIVER DELTA

摘要

Overwintering tarnished plant bug adults, Lygus lineolaris (Palisot de Beauvois), were collected near Stoneville, MS, from henbit, Lamium amplexicaule L., or plant debris during December 2003 and January 2004 and dissected to determine their reproductive status. Diapause in adults collected from henbit was broken during December, and most males and females were reproductive by the end of December. Adults collected from plant debris were in a more intense diapause which was broken during January, andmost adults were reproductive by the end of January. Previous research showed that in winters when henbit bloomed in December through March new generation adults were produced on henbit by mid-March. In the current study, a cold period from mid-January through mid-February stunted henbit and new generation adults were not produced on henbit until April. This new generation produced in April resulted from adults that overwintered in plant debris along with any surviving adults that overwintered on henbit. These adults utilized henbit that began to regrow and bloom in late-February along with other hosts that bloomed in March and April. Our results again showed that the tarnished plant bug has an overwintering population with two intensities of diapause.This enabled the tarnished plant bug to produce new generation adults in March and April in warm winters in the mid-South. In winters with cold periods that kill or stunt winter hosts, the part of the population that breaks diapause in January is better able to survive and produce new generation adults in April. The tarnished plant bug is well adapted to its winter habitat in the mid-South.